SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '694484e0102aded856d097fba6df6283def8ba76918c8260573a164993477d4c' 
  AND token = 'z0dJZ103hRK8oF08r+Vx3gJAZefAzssDO4ZMGNmZys4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}